Analysis of endoderm formation in the avian blastoderm by the use of quail-chick chimaeras

Development ◽  
1977 ◽  
Vol 41 (1) ◽  
pp. 209-222
Author(s):  
J. Fontaine ◽  
N. M. Le Douarin
Keyword(s):  
Neural Crest ◽  
Endocrine Cells ◽  
Primitive Streak ◽  
Germ Layer ◽  
Chick Embryos ◽  
Germ Layers ◽  
Enteric Ganglia ◽  
Gut Epithelium ◽  
Migration Of Cells ◽  
Chick And Quail Embryos

The formation of the endoderm has been investigated in chimaeric embryos resulting from the combination of the lower and upper germ layers taken from chick and quail embryos at stages 2–6 of Vakaët (1962). The ability to recognize quail from chick cells made it possible to follow the fate of each germ layer during development. It appeared that the primitive hypoblast participates in the formation of the anterolateral extra-embryonic endoderm while the embryonic endoderm is formed later by migration of cells of the ectomesoblast through Hensen's node and the primitive streak. Further interspecific combinations were carried out between ectoderm and endoderm + mesoderm from quail and chick embryos at stages 5–7 of Hamburger and Hamilton. The explants were grafted into chick embryos for several days and the intestinal structures which developed were observed. No contribution of cells from the neurectoderm to the endoderm was found. In contrast, cells coming from the neural crest colonized the intestinal structures and gave rise to the enteric ganglia. It was concluded from these observations that the enterochromaffin and endocrine cells of the gut epithelium do not originate from the neurectoderm.

Is there a ventral neural ridge in chick embryos? Implications for the origin of adenohypophyseal and other APUD cells

Development ◽  
1980 ◽  
Vol 57 (1) ◽  
pp. 71-78
Author(s):  
N. B. Levy ◽  
Ann Andrew ◽  
B. B. Rawdon ◽  
Beverley Kramer
Keyword(s):  
Neural Crest ◽  
Endocrine Cells ◽  
Ventral Surface ◽  
Neural Plate ◽  
Chick Embryos ◽  
Serial Sections ◽  
Apud Cells ◽  
Surface Ectoderm ◽  
Neural Ectoderm ◽  
Thickened Surface

Two- to ten-somite chick embryos were studied in order to ascertain whether, as has been proposed, there exists a ‘ventral neural ridge’ which gives rise to the hypophyseal (Rathke's) pouch. Serial sections and stereo-microscopy were used. The neural ridges arch around the rostral end of the embryo onto the ventral surface of the head, but no evidence was found for their extension to form a ‘ventral neural ridge’ reaching the stomodaeum: in fact a considerable expanse of non-thickened surface ectoderm was seen to separate the ventral portions of the neural ridges from the stomodaeum. The thickening of neural ectoderm which does appear on the ventral surface of the head results from apposition and fusion of the opposite neural ridges flanking the neural plate and thus the tip of the anterior neuropore - the classically accepted mode of closure of the neuropore. These findings are in accord with the generally accepted concept of the origin of thehypophyseal pouch rather than with its derivation from a ‘ventral neural ridge’. No sign of neural crest formation was encountered ventrally; this observation excludes the possibility that endocrine cells of the APUD series could originate from neural crest in this region.

The differentiation of neural crest cells into visceral cartilages and odontoblasts in Amblystoma , and a re-examination of the germ-layer theory

1947 ◽  
Vol 134 (876) ◽  
pp. 377-398 ◽  
Keyword(s):  
Neural Crest ◽  
Normal Development ◽  
Neural Crest Cells ◽  
Early Embryo ◽  
Critical Study ◽  
Germ Layer ◽  
Germ Layers ◽  
Classical Form ◽  
Endodermal Cells ◽  
Dermal Bones

A critical study and demonstration of the distribution of yolk globules and of pigment granules in normal development of the axolotl shows that these cell inclusions can be regarded as infallible evidence of the origin of cells from endo-mesoderm or from ectoderm layers of the embryo respectively. It is demonstrated that ectodermal cells of the neural crest differentiate into the cartilages of the visceral arches, into odontoblasts, and it is more than probable that they differentiate into osteoblasts of dermal bones. It is further demonstrated that the enamel organs of the teeth can be formed from the ectodermal cells of the stomodaeal collar, from the endodermal cells of the gut wall, or from both. The germ-layer theory is examined as regards its theoretical implications in connexion with the homology of structures in the adult and the presumptive organ-forming regions of the early embryo. It is found that there is no invariable correlation between the germ layers and either the presumptive organ-forming regions or the formed structures. It follows that the germ layers are not determinants of differentiation in development, but embryonic structures which resemble one another closely in different forms although they may contain materials differing in origin and in fate. The germ -layer theory in its classical form must therefore be abandoned.

Mesenchymal derivatives of the neural crest: analysis of chimaeric quail and chick embryos

Development ◽  
1975 ◽  
Vol 34 (1) ◽  
pp. 125-154
Author(s):  
C. S. Le Lièvre ◽  
N. M. Le Douarin
Keyword(s):  
Neural Crest ◽  
Carotid Arteries ◽  
Secretory Cells ◽  
Chick Embryos ◽  
Digestive Tube ◽  
Enteric Ganglia ◽  
Lower Jaw ◽  
Branchial Arches ◽  
Neural Axis ◽  
Common Carotid Arteries

Interspecific grafts of neural tube and associated neural crest (NC) have been made between quail and chick embryos. Structural differences of the interphase nucleus in the two species make it possible to identify quail from chick cells in the chimaeras after Feulgen—Rossenbeck's staining and at the electron microscope level. Owing to the stability of the natural quail nuclear marker labelling, migration pattern and developmental fate of the grafted NC cells could be followed in the host embryo. In previous work it has been demonstrated that the visceral skeleton derives entirely from NC mesenchyme and the various levels of the neural axis from which visceral cartilages and bones originate have been established. In the present work, the contribution to the lower jaw and pharynx of NC mesenchymal derivatives other than bones and cartilages has been studied. It is shown that the dermis in the face and ventrolateral side of the neck has a neural origin. The wall of the large arteries deriving from the branchial arches (systemic aorta, pulmonary arteries, brachiocephalic trunks and common carotid arteries) are entirely made up of mesectodermal cells except for the endothelial epithelium which is mesodermal in origin. The presence in the wall of the common carotid arteries of fiuorogenic monoamines-containing cells is demonstrated using the formol-induced-fiuorescence technique. Like the secretory cells of the carotid body, the fluorescent cells of the carotid artery wall originate from the rhombencephalic NC. Connective tissue of the lower jaw, tongue and ventrolateral part of the neck originate from the neural crest. Mesectoderm participate in the formation of the glands associated with the tongue and pharynx (lingual gland, thymus, thyroid, parathyroids) giving their mesenchymal component. On the other hand, as demonstrated previously by our group, NC cells are the main cellular component of the UB since they give rise to the calcitoninproducing cells. The wall of the oesophagus and trachea is of mesodermal origin, but adipose tissue around the trachea and parasympathetic enteric ganglia of the digestive tube derives from NC. NC cells participate in the formation of striated muscles of the branchial arches and differentiate there into connective and muscle cells. It appears from this study that the differentiating capabilities are similar in mesenchymal and mesectodermal cells with the exception of blood vessel endothelia which in our experiments are always of host origin in mesectoderm-derived tissues. The capacity of the NC to give rise to mesenchymal derivatives is restricted to the cephalic neural axis down to the level of the 5th somite in both chick and quail embryos.

Cardiac neural crest ablation inhibits compaction and electrical function of conduction system bundles

2007 ◽  
Vol 292 (3) ◽  
pp. H1291-H1300 ◽  
Author(s):  
Abhijit Gurjarpadhye ◽  
Kenneth W. Hewett ◽  
Charles Justus ◽  
Xuejun Wen ◽  
Harriett Stadt ◽  
...  
Keyword(s):  
Neural Crest ◽  
Conduction System ◽  
Lineage Tracing ◽  
Chick Embryos ◽  
Myocardial Cells ◽  
Cardiac Neural Crest ◽  
His Bundle ◽  
Electrical Connections ◽  
Migration Of Cells ◽  
Ventricular Conduction

Retroviral and transgenic lineage-tracing studies have shown that neural crest cells associate with the developing bundles of the ventricular conduction system. Whereas this migration of cells does not provide progenitors for the myocardial cells of the conduction system, the question of whether neural crest affects the differentiation and/or function of cardiac specialized tissues continues to be of interest. Using optical mapping of voltage-sensitive dye, we determined that ventricles from chick embryos in which the cardiac neural crest had been laser ablated did not progress to apex-to-base activation by the expected stage [i.e., Hamburger and Hamilton (HH) 35] but instead maintained basal breakthroughs of epicardial activation consistent with immature function of the conduction system. In direct studies of activation, waves of depolarization originating from the His bundle were found to be uncommon in control hearts from HH34 and HH35 embryos. However, activations propagating from septal base, at or near the His bundle, occurred frequently in hearts from HH34 and HH35 neural crest-ablated embryos. Consistent with His bundle cells maintaining electrical connections with adjacent working myocytes, histological analyses of hearts from neural crest-ablated embryos revealed His bundles that had not differentiated a lamellar organization or undergone a process of compaction and separation from surrounding myocardium observed in controls. Furthermore, measurements on histological sections from optically mapped hearts indicated that, whereas His bundle diameter in control embryos thinned by almost one-half between HH30 and HH34, the His bundle in ablated embryos underwent no such compaction in diameter, maintaining a thickness at HH30, HH32, and HH34 similar to that observed in HH30 controls. We conclude that the cardiac neural crest is required in a novel function involving lamellar compaction and electrical isolation of the basally located His bundle from surrounding myocardium.

scholarly journals Further evidence that enterochromaffin cells are not derived from the neural crest

Development ◽  
1974 ◽  
Vol 31 (3) ◽  
pp. 589-598
Author(s):  
Ann Andrew
Keyword(s):  
Neural Crest ◽  
Neural Crest Cells ◽  
Enterochromaffin Cells ◽  
Lateral Part ◽  
Time Of Arrival ◽  
Chick Embryos ◽  
Process Stage ◽  
Somite Stage ◽  
Enteric Ganglia ◽  
Probable Time

Recently, a previous finding that the enterochromaffin cells of chick embryos are not derived from the neural crest has been contested, and so further evidence has been sought. Presumptive gut, i.e. endoderm and adherent mesoderm, of embryos between the short head-process stage and the 25-somite stage was grown on the chorio-allantoic membranes of host embryos. Whether the presumptive gut was excised before or after the probable time of arrival of neural crest cells in the gut, enterochromaffin cells occurred in the intestine in the grafts. The presence or absence of enteric ganglia indicated the presence or absence, respectively, of neural crest cells. Enterochromaffin cells were plentiful even if the donor had been at a stage preceding that at which cells of the neural crest start to migrate, or preceding that at which the crests themselves first appear. In a second experiment, presumptive gut of embryos at 10- to 21-somite stages was excised so as to exclude the portion underlying the somites. Enteric ganglia were lacking in the intestine of these grafts, but enterochromaffin cells were invariably present. These experiments show that the precursors of enterochromaffin cells are present in the more lateral part of the presumptive gut before the neural crest precursors of enteric ganglia reach the region; and that they are present in the presumptive gut long before any crest cells could have arrived there. This evidence supports the view that enterochromaffin cells are not derived from the neural crest in chick embryos.

The effect of pancreatic mesenchyme on the differentiation of endocrine cells from gastric endoderm

Development ◽  
1987 ◽  
Vol 100 (4) ◽  
pp. 661-671 ◽  
Author(s):  
B. Kramer ◽  
A. Andrew ◽  
B.B. Rawdon ◽  
P. Becker
Keyword(s):  
Endocrine Cell ◽  
Endocrine Cells ◽  
Cell Types ◽  
The Other ◽  
Chick Embryos ◽  
Cell Type ◽  
Pancreatic Insulin ◽  
Somatostatin Cells ◽  
Regional Specificity ◽  
Gut Endocrine Cells

To determine whether mesenchyme plays a part in the differentiation of gut endocrine cells, proventricular endoderm from 4- to 5-day chick or quail embryos was associated with mesenchyme from the dorsal pancreatic bud of chick embryos of the same age. The combinations were grown on the chorioallantoic membranes of host chick embryos until they reached a total incubation age of 21 days. Proventricular or pancreatic endoderm of the appropriate age and species reassociated with its own mesenchyme provided the controls. Morphogenesis in the experimental grafts corresponded closely to that in proventricular controls, i.e. the pancreatic mesenchyme supported the development of proventricular glands from proventricular endoderm. Insulin, glucagon and somatostatin cells and cells with pancreatic polypeptide-like immunoreactivity differentiated in the pancreatic controls. The latter three endocrine cell types, together with neurotensin and bombesin/gastrin-releasing polypeptide (GRP) cells, developed in proventricular controls and experimental grafts. The proportions of the major types common to proventriculus and pancreas (somatostatin and glucagon cells) were in general similar when experimental grafts were compared with proventricular controls but different when experimental and pancreatic control grafts were compared. Hence pancreatic mesenchyme did not materially affect the proportions of these three cell types in experimental grafts, induced no specific pancreatic (insulin) cell type and allowed the differentiation of the characteristic proventricular endocrine cell types, neurotensin and bombesin/GRP cells. However, an important finding was a significant reduction in the proportion of bombesin/GRP cells, attributable in part to a decrease in their number and in part to an increase in the numbers of endocrine cells of the other types. This indicates that mesenchyme may well play a part in determining the regional specificity of populations of gut endocrine cells.

A single morphogenetic field gives rise to two retina primordia under the influence of the prechordal plate

Development ◽  
1997 ◽  
Vol 124 (3) ◽  
pp. 603-615 ◽  
Author(s):  
H. Li ◽  
C. Tierney ◽  
L. Wen ◽  
J.Y. Wu ◽  
Y. Rao
Keyword(s):  
Expression Pattern ◽  
Lineage Tracing ◽  
Chick Embryos ◽  
Median Region ◽  
Prechordal Plate ◽  
Prechordal Mesoderm ◽  
New Gene ◽  
Vertebrate Embryos ◽  
Migration Of Cells ◽  
Anterior Neural Plate

Two bilaterally symmetric eyes arise from the anterior neural plate in vertebrate embryos. An interesting question is whether both eyes share a common developmental origin or they originate separately. We report here that the expression pattern of a new gene ET reveals that there is a single retina field which resolves into two separate primordia, a suggestion supported by the expression pattern of the Xenopus Pax-6 gene. Lineage tracing experiments demonstrate that retina field resolution is not due to migration of cells in the median region to the lateral parts of the field. Removal of the prechordal mesoderm led to formation of a single retina both in chick embryos and in Xenopus explants. Transplantation experiments in chick embryos indicate that the prechordal plate is able to suppress Pax-6 expression. Our results provide direct evidence for the existence of a single retina field, indicate that the retina field is resolved by suppression of retina formation in the median region of the field, and demonstrate that the prechordal plate plays a primary signaling role in retina field resolution.

Studies on self-differentiating and induction capacities of Hensen's node using intracoelomic grafting technique

Development ◽  
1972 ◽  
Vol 28 (3) ◽  
pp. 547-558
Author(s):  
J. R. Viswanath ◽  
Leela Mulherkar
Keyword(s):  
Chick Embryo ◽  
Neural Tissue ◽  
Primitive Streak ◽  
Germ Layer ◽  
Grafting Technique ◽  
Definite Combination

Living Hensen's node of the definitive primitive streak of chick embryo was prepared into ‘sandwiches’ with the competent ectoderm and the sandwich grafts were transplated into the 2·5 day chick embryo using the intracoelomic grafting technique of Hamburger. One hundred and twenty-four grafts were prepared and transplanted intracoelomically, 28 grafts were lost due to the death of the host embryos, 63 grafts did not differentiate at all, but 33 well-defined grafts were recovered, after cultivating the transplanted hosts for 12–14 days. All kinds of tissues from feather germs to neural tissue were found to have differentiated in the grafts. The more frequently occurring tissues were feather germs, epidermal vesicle, neural tissue, kidney and muscle. Other differentiations were the cartilage notochord and gut. No definite combination pattern has emerged from the tissues. But when the tissues were traced to their germ-layer derivation, 22 of them belonged to the mesodermal complex, 11 to the ectodermal complex and 8 to the endodermal complex. In the light of the above results, the probable existence of a mesodermal factor and an ectodermal factor independently responsible for the respective differentiations, as also the competence of the ectoderm, is discussed.

The distribution of endocrine cell progenitors in the gut of chick embryos

Development ◽  
1984 ◽  
Vol 82 (1) ◽  
pp. 131-145
Author(s):  
B. B. Rawdon ◽  
Beverley Kramer ◽  
Ann Andrew
Keyword(s):  
Gastrointestinal Tract ◽  
Progenitor Cells ◽  
Digestive Tract ◽  
Pancreatic Polypeptide ◽  
Endocrine Cell ◽  
Endocrine Cells ◽  
Chick Embryos ◽  
Intact Embryo ◽  
Pancreatic Endocrine Cells ◽  
Gut Endocrine Cells

The aim of this experiment was to find out whether or not, at early stages of development, progenitors of the various types of gut endocrine cells are localized to one or more specific regions of the gastrointestinal tract. Transverse strips of blastoderm two to four somites in length were excised between the levels of somites 5 and 27 in chick embryos at 5- to 24-somite stages and were cultured as chorioallantoic grafts. The distribution of endocrine cells in the grafts revealed confined localization of progenitor cells only in the case of insulinimmunoreactive cells. Theprogenitors of cells with somatostatin-, pancreatic polypeptide-, glucagon-, secretin-, gastrin/CCK-, motilin-, neurotensin- and serotonin-like immunoreactivity were distributed along the length of the presumptive gut at the time of explantation; indeed, in many cases they were more widespread than are their differentiated progeny in normal gut of the same age. This finding indicates that conditions in grafts must differ from those that operate in the intact embryo. Also it may explain the occurrence of ectopic gut or pancreatic endocrine cells in tumours of the digestive tract.

Sign in / Sign up

Export Citation Format

Share Document